In 1832 Taylor followed his family to Toronto, Canada, where he joined the Mormon Church in 1836. Ordained an apostle in 1838, he proselyted in the British Isles, France, and Germany. While in Europe he supervised the translation and publication of the Book of Mormon in a French and a German edition. In Nauvoo, Illinois, Taylor proved to be a capable writer and journalist. He edited the Times and Seasons from 1842 to 1846, and the Nauvoo Neighbor from 1843 to 1846. He founded the L'Etoile du Deseret ("Star of Deseret") in France, and Zion's Panier ("Zion's Banner") in Germany in 1851. In New York City he published a series, The Mormons, from 1854 to 1857. His more than twenty pamphlets and a book in defense of Mormon beliefs and practices earned him the appellation "Champion of Liberty" from his believers.

Taylor, shot five times, was with Joseph and Hyrum Smith when they were assassinated by a mob in Carthage jail. He was thereafter known by some as a "living martyr." In 1847, with Parley P. Pratt, Taylor led 1,500 pioneers from Winter Quarters to Salt Lake Valley, where he helped found Utah's sugar-manufacturing industry in 1852. A naturalized American citizen, he was elected to the territorial legislature from 1854 to 1876 and served as territorial superintendent of schools in 1877. Presiding over the Mormon Church as its third president from 1877 to 1887, he approved the Primary Association for children and founded Zion's Central Board of Trade, an economic cooperative organization (1878). During the church's Jubilee Year celebration in 1880, he reorganized the First Presidency, forgave debts owed to the Perpetual Emigrating Company by the poor, and canonized the Pearl of Great Price as scripture. The Assembly Hall on Temple Square (1882) and the Logan Temple (1884) were completed and dedicated under his direction.

Passage of the Edmunds Law in 1882, severely penalizing polygamists, led President Taylor to establish Mormon colonies of refuge in Mexico and Canada. Taylor refused to abandon the Mormon practice of plural marriage despite the increased pressure from U.S. authorities. He was forced into hiding--"on the underground," as the Mormons called it--to avoid arrest and imprisonment. He married fifteen wives and had thirty-five children. He withdrew from public view in 1885 and died in hiding while in Kaysville, Utah, on 25 July 1887. His motto was "The Kingdom of God or Nothing."

See: Francis M. Gibbons, John Taylor, Mormon Philosopher, Prophet of God (1985); B.H. Roberts, The Life of John Taylor (1892); John Taylor, Gospel Kingdom (1943); Samuel W. Taylor, The Kingdom or Nothing (1976); John Taylor, The John Taylor Papers (1984).